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Germacrene

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Germacrenes
(–)-Germacrene A
Names
IUPAC name
(1E,5E,8S)-1,5-dimethyl-8-(prop-1-en-2-yl)cyclodeca-1,5-diene
Other names
  • (−)-Germacrene A
  • (E,E)-Germacra-3,9,11-triene
  • (1E,5E,8S)-1,5-dimethyl-8-(1-methylethenyl)-1,5-cyclodecadiene
  • (S-(E,E))-1,5-dimethyl-8-(1-methylethenyl)-1,5-cyclodecadiene
Identifiers
3D model (JSmol)
6500908 (A) 1864177 (D)
ChEBI
ChEMBL
ChemSpider
KEGG
  • InChI=1S/C15H26/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,12,15H,5,7-8,10-11H2,1-4H3/b13-6+,14-9+/t15-/m0/s1 X markN
    Key: YDLBHMSVYMFOMI-SDFJSLCBSA-N X markN
  • InChI=1/C15H26/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,12,15H,5,7-8,10-11H2,1-4H3/b13-6+,14-9+/t15-/m0/s1
    Key: YDLBHMSVYMFOMI-SDFJSLCBBV
  • A: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,15H,1,5,7-8,10-11H2,2-4H3/b13-6+,14-9+/t15-/m1/s1
    Key: XMRKUJJDDKYUHV-DFSVIBJJSA-N
  • D: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h7-8,10,12,15H,3,5-6,9,11H2,1-2,4H3/b10-8-,14-7-
    Key: GAIBLDCXCZKKJE-BZXLUOIMSA-N
  • E: InChI=1S/C15H24/c1-12(2)15-10-8-13(3)6-5-7-14(4)9-11-15/h6,9,11,14-15H,1,5,7-8,10H2,2-4H3/b11-9+,13-6+
    Key: OAOGSSAAVUPEKA-BMCYRRRCSA-N
  • C/C/1=C\CC/C(=C/C[C@H](CC1)C(C)C)/C
  • A: C/C/1=C\CC/C(=C/C[C@@H](CC1)C(=C)C)/C
  • B: C/C/1=C\CC/C(=C/CC(=C(C)C)CC1)/C
  • C: C/C/1=C\CC/C(=C/C=C(\CC1)/C(C)C)/C
  • E: CC\1CC/C=C(/CCC(/C=C1)C(=C)C)\C
Properties
C15H24
Molar mass 204.35 g/mol
Density 0.793 g/mL
Boiling point 236.4 °C (457.5 °F; 509.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Germacrenes are a group of naturally occurring volatile organic hydrocarbons of the sesquiterpene and cycloalkene class. They are typically produced in plants and have antimicrobial and insecticidal properties, though they also play a role as insect pheromones. Two prominent molecules are germacrene A and germacrene D.

Structures

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Germacrene has five structural isomers.[1]

Germacrene isomers
Germacrene A Germacrene B Germacrene C Germacrene D Germacrene E
(–)-Germacrene AGermacrene BGermacrene CGermacrene DGermacrene E

Germacrene A is chiral and both the (–)-(S) and (+)-(R) forms are found naturally.[1] Germacrene D is also known in both enantiomeric forms.[2]

Natural occurrences

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The essential oils of deadnettles (genus Lamium),[3] hedgenettles (genus Stachys),[4] and Clausena anisata are characterized by their high contents of germacrene D. Germacrene B is a major component of patchouli oil.[5]

Metabolism in plants

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The germacrenes are precursors to sesquiterpene lactones.[6] For example, the enzyme germacrene A hydroxylase in chicory converts (+)-germacrene A to a carboxylic acid which is the starting material for costunolide synthase, which converts it to costunolide:[7][8]

2D representation of the chemical structure of Q27104477.
(+)-germacrene A
Oxidase
 
 
Rightward reaction arrow
 
 
 
2D representation of the chemical structure of Q27131000.
(+)-germacrene A acid
Synthase
 
 
Rightward reaction arrow
 
 
 
2D representation of the chemical structure of costunolide .
costunolide

References

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  1. 1 2 Adio, A. M. (2009). "Germacrenes A–E and related compounds: thermal, photochemical and acid induced transannular cyclizations". Tetrahedron. 65 (8): 1533–1552. doi:10.1016/j.tet.2008.11.050.
  2. ↑ Arimura, G.-I.; Huber, D. P. W.; Bohlmann, J. (2004). "Forest tent caterpillars (Malacosoma disstria) induce local and systemic diurnal emissions of terpenoid volatiles in hybrid poplar (Populus trichocarpa × deltoides): cDNA cloning, functional characterization, and patterns of gene expression of (−)-germacrene D synthase, PtdTPS1". The Plant Journal. 37 (4): 603–616. doi:10.1111/j.1365-313X.2003.01987.x. PMID 14756770.
  3. ↑ Flamini, G.; Cioni, P. L.; Morelli, I. (2005). "Composition of the essential oils and in vivo emission of volatiles of four Lamium species from Italy: L. purpureum, L. hybridum, L. bifidum and L. amplexicaule". Food Chemistry. 91 (1): 63–68. doi:10.1016/j.foodchem.2004.05.047.
  4. ↑ Morteza-Semnani, K.; Akbarzadeh, M.; Changizi, Sh. (2005-11-01). "Essential oils composition of Stachys byzantina, S. inflata, S. lavandulifolia and S. laxa from Iran". Flavour and Fragrance Journal. 21 (2): 300–303. doi:10.1002/ffj.1594.
  5. ↑ Hasegawa, Yoshihiro; Tajima, Katsuhiko; Toi, Nao; Sugimura, Yukio (1992). "An additional constituent occurring in the oil from a patchouli cultivar". Flavour and Fragrance Journal. 7 (6): 333–335. doi:10.1002/ffj.2730070608. ISSN 0882-5734.
  6. ↑ Ghantous, Akram; Gali-Muhtasib, Hala; Vuorela, Heikki; Saliba, Najat A.; Darwiche, Nadine (2010). "What Made Sesquiterpene Lactones Reach Cancer Clinical Trials?". Drug Discovery Today. 15 (15–16): 668–678. doi:10.1016/0305-1978(86)90101-8. PMID 20541036.
  7. ↑ de Kraker JW, Franssen MC, Dalm MC, de Groot A, Bouwmeester HJ (April 2001). "Biosynthesis of germacrene A carboxylic acid in chicory roots. Demonstration of a cytochrome P450 (+)-germacrene a hydroxylase and NADP+-dependent sesquiterpenoid dehydrogenase(s) involved in sesquiterpene lactone biosynthesis". Plant Physiology. 125 (4): 1930–40. doi:10.1104/pp.125.4.1930. PMC 88848. PMID 11299372.
  8. ↑ de Kraker JW, Franssen MC, Joerink M, de Groot A, Bouwmeester HJ (May 2002). "Biosynthesis of costunolide, dihydrocostunolide, and leucodin. Demonstration of cytochrome p450-catalyzed formation of the lactone ring present in sesquiterpene lactones of chicory". Plant Physiology. 129 (1): 257–68. doi: